While the increased functionality of portable telephones has been accompanied by the incorporation of various functions, recent years have also witnessed the necessity for designs and functions that match the user's preferences regarding, for example, case designs, images, and melodies. The method of communicating information from a portable telephone to a user is implemented by way of indicators such as liquid crystal screens, but schemes other than communicating by way of a liquid crystal screen are necessary for the display and presentation of various types of information. However, light-emitting elements that can be used apart from communicating by of a liquid crystal screen in a portable telephone are limited to incoming message LEDs and LEDs arranged on the exterior side of the case. In addition, key backlights that are incorporated for illuminating keys merely light all or a portion of the keys in a single color.
Prior art exists as a lighting method for communicating information to a user in a portable terminal apparatus in which a color produced on the liquid crystal screen is matched to a color produced in the key backlights to guide the user to a target function (for example, see Patent Document 1). In the method described in Patent Document 1, color values relating to an event are determined, display is implemented on a liquid crystal screen with the determined color values while simultaneously lighting the key backlights with the same color to alert the user to an event from the color and to guide the user to the event displayed on the liquid crystal screen.